selftests/bpf: Reject graph kptr use after RCU unlockgrafted

Add a sleepable verifier test that loads a graph-node local kptr in an
explicit RCU read-side critical section, then passes its node to
bpf_rbtree_remove() after the section ends.

Before the verifier fix, the stale NON_OWN_REF flag makes the node look like
a live borrowed reference and the program is accepted. After the fix, the
pointer is demoted without NON_OWN_REF and the graph kfunc argument is
rejected.

Also exercise a graph kptr loaded while a spin lock provides implicit RCU
protection. The pointer must be invalidated when the lock is released, which
guards the required ordering between non-owning-reference invalidation and
RCU demotion.

Update the existing fault-protected load test state description. The
post-unlock pointer no longer carries NON_OWN_REF, but remains readable
because the load is rewritten to use BPF_PROBE_MEM.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260904084325.52250-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 84 insertions, 0 deletions

diff --git a/drivers/hid/usbhid/Kconfig b/drivers/hid/usbhid/Kconfig
new file mode 100644
index 000000000..f3194767a
--- /dev/null
+++ b/drivers/hid/usbhid/Kconfig
@@ -0,0 +1,84 @@
+# SPDX-License-Identifier: GPL-2.0-only
+menu "USB HID support"
+	depends on USB
+
+config USB_HID
+	tristate "USB HID transport layer"
+	default y
+	depends on HID
+	help
+	  Say Y here if you want to connect USB keyboards,
+	  mice, joysticks, graphic tablets, or any other HID based devices
+	  to your computer via USB, as well as Uninterruptible Power Supply
+	  (UPS) and monitor control devices.
+
+	  You can't use this driver and the HIDBP (Boot Protocol) keyboard
+	  and mouse drivers at the same time. More information is available:
+	  <file:Documentation/input/input.rst>.
+
+	  If unsure, say Y.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called usbhid.
+
+comment "Input core support is needed for USB HID input layer or HIDBP support"
+	depends on USB_HID && INPUT=n
+
+config HID_PID
+	bool "PID device support"
+	help
+	  Say Y here if you have a PID-compliant device and wish to enable force
+	  feedback for it. Microsoft Sidewinder Force Feedback 2 is one of such
+	  devices.
+
+config USB_HIDDEV
+	bool "/dev/hiddev raw HID device support"
+	depends on USB_HID
+	help
+	  Say Y here if you want to support HID devices (from the USB
+	  specification standpoint) that aren't strictly user interface
+	  devices, like monitor controls and Uninterruptible Power Supplies.
+
+	  This module supports these devices separately using a separate
+	  event interface on /dev/usb/hiddevX (char 180:96 to 180:111).
+
+	  If unsure, say Y.
+
+menu "USB HID Boot Protocol drivers"
+	depends on USB!=n && USB_HID!=y && EXPERT
+
+config USB_KBD
+	tristate "USB HIDBP Keyboard (simple Boot) support"
+	depends on USB && INPUT
+	help
+	  Say Y here only if you are absolutely sure that you don't want
+	  to use the generic HID driver for your USB keyboard and prefer
+	  to use the keyboard in its limited Boot Protocol mode instead.
+
+	  This is almost certainly not what you want.  This is mostly
+	  useful for embedded applications or simple keyboards.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called usbkbd.
+
+	  If even remotely unsure, say N.
+
+config USB_MOUSE
+	tristate "USB HIDBP Mouse (simple Boot) support"
+	depends on USB && INPUT
+	help
+	  Say Y here only if you are absolutely sure that you don't want
+	  to use the generic HID driver for your USB mouse and prefer
+	  to use the mouse in its limited Boot Protocol mode instead.
+
+	  This is almost certainly not what you want.  This is mostly
+	  useful for embedded applications or simple mice.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called usbmouse.
+
+	  If even remotely unsure, say N.
+
+endmenu
+
+endmenu